Sculpt lean muscle"As you age, you start to lose some muscle mass," says Geralyn Coopersmith, an exercise physiologist and national director of the Equinox Fitness Training Institute. "Lifting weights helps you maintain and build on what you have, so your metabolism stays high."

Sculpt lean muscle"As you age, you start to lose some muscle mass," says Geralyn Coopersmith, an exercise physiologist and national director of the Equinox Fitness Training Institute. "Lifting weights helps you maintain and build on what you have, so your metabolism stays high."